Drug Discov Ther. 2009;3(4):168-175.
A novel liquid effervescent floating delivery system for sustained drug delivery.
An effervescent floating liquid formulation with in situ gelling properties has been assessed for its potential for sustaining drug delivery and targeting. The formulation consisted of sodium alginate and glyceryl monooleate (GMO). The developed formulation met all pre-requisites to become an in situ gelling floating system and it gelled and floated instantaneously in the pH conditions of the stomach. Moreover, the gels formed in situ remained intact for more than 48 h to facilitate sustained release of drugs. Increasing the mannuronic acid ratio of sodium alginate and the GMO concentration significantly retarded the release rate and extent. The in vitro release of both hydrophilic and hydrophobic drugs from the prepared formulations followed root-time kinetics during the sustained release period. Replacing the free drug with drug encapsulated microspheres enabled tailoring of the release profile and achieved zero-order release kinetics. The system retained its appearance and rheological properties for 12 months at ambient conditions. The values of the similarity factor Sd proved the absence of any significant difference in the release profile upon storage.